The present invention relates to recording and reproducing video signals on a magnetic disc and, more particularly, relates to a specialized system for use in varying the speed of motion within a display produced from such signals.
There have been many systems proposed for playback of variable speed video information. One such system currently in use employs a rigid metallic disc having a suitable magnetic surface applied to both sides. A magnetic head is located relative to each surface and special actuators accurately control the radial positioning of the two heads with respect to the disc. Magnetic discs of the type under discussion are relatively difficult to manufacture, since they require an extremely fine surface finish. In contrast, plastic discs, which are used for computer memory storage and the like, and which are called floppy discs, have not, in general, been used with video recorders since the tolerances of such floppy discs are insufficiently controlled. Typically, the system in question utilizes a recording head arrangement which records video frame information in concentric circles on the record media and, as discussed above, records on both sides of the record media.
Other known video recording systems record video frames, serially and spirally, on one side of a record disc. In order for such systems to reproduce recorded video signals so as to effect slow motion, stop motion, or speeded-up motion, complex electronic apparatus is necessary.